This invention relates to improvements in the method and apparatus for analysis of constituents carried in a fibrous or porous medium set forth in the commonly-assigned and copending U.S. Pat. No. 4,059,405, issued Nov. 22, 1977. The disclosure of that patent is incorporated herein by this reference. The referenced patent issued on application Ser. No. 715,855, which is a continuation-in-part of abandoned copending application Ser. No. 498,646 for "Method And Apparatus For Analysis Of Constituent Carried In Fibrous Medium" filed Aug. 19, 1974; which is a continuation-in-part of the abandoned copending application Ser. No. 243,068 for "Method For Constituent Analysis With Thin-Layer Reactant Mixture" filed Apr. 11, 1972.
A general object of this invention is to provide improved apparatus, articles and compositions, and improved methods, for chemical spot test analysis, with an optically thin concentration of a measured reaction product, which enhance the precision of analysis, which facilitate performing the analysis, and which expand the uses of such analysis.
One specific object of the invention is to provide improvement of a fibrous or other porous medium for use in chemical spot test analysis and which is pretreated to bear at least some reagent for producing the reaction product of measurement with an optically thin concentration.
Another specific object of the invention is to provide a disposable article for enhancing the delivery of liquid to a reaction medium for use in chemical spot test analysis of the above character.
A further feature of the invention is to provide improved instrument structure for enhancing the repeatability and precision of chemical spot test analysis measurements with an optically thin concentration of the measured reaction product.
Other objects of the invention will in part be obvious and will in part appear hereinafter.